\begin{lstlisting}[caption=全局作用域,label=src:scope2]
|\begin{tikzpicture}[overlay]
\draw [->,thick] (2.9,-5.00) arc (-60:90:2.00cm);
\draw [->,thick] (3.5,-7.00) arc (-60:90:3.15cm);
\end{tikzpicture}|
package main

var a = 6

func main() {
    p()
    q()
    p()
}

func p() {
    println(a)
}

func q() {
    a = 5|\coderemark{赋值}|
    println(a)
}
\end{lstlisting}
